Controllers and methods for a fuel injected internal combustion engine

ABSTRACT

An internal combustion engine has a fuel injector that is controlled by an engine control unit. According to one embodiment a device receives from a temperature sensor information corresponding to the temperature of the engine. The device transmits substitute temperature information to the engine control unit when the temperature of the engine is within a predetermined range of temperatures. The substitute temperature information corresponds to a temperature that is different than the actual temperature of the ICE. The engine control unit controls the fuel injector so that it operates in response to the substitute temperature information.

1. FIELD OF INVENTION

Embodiments of the present invention generally relate to controllers andmethods for a fuel injected internal combustion engine (ICE), andparticularly controllers and methods for controlling the fuel injectorin a predetermined response to the ICE reaching at least onepredetermined parameter of the ICE.

2. BACKGROUND

In the art of the internal combustion engine (ICE), a device istypically needed to mix air and fuel, the mixture of which is thendelivered to the ICE's combustion chamber. This mixture is usuallydelivered toward the end of the ICE's compression stroke, and thenignited using, for example, a spark plug. In the past, this mixing anddelivering was achieved through the use of a carburetor. Over morerecent years however, fuel injectors have increasingly replaced thecarburetor as the preferred means to deliver fuel to the ICE'scombustion chamber. (See generally U.S. Pat. No. 3,430,616 to Glöckler)

A fuel injector vaporizes (atomizes) fuel by pumping it in controlledamounts and under high force through a nozzle (spray tip). Fuel injectorcomponents typically include a plunger covering a valve opening. In manyinstances, the plunger is retracted upon activation of an electronicvalve solenoid. This allows pressurized fuel to flow into an atomizerand out of a spray tip. Once the valve solenoid is deactivated, a valvespring returns the plunger to its at-rest position covering the valveopening. Timing the activation of the valve solenoid is controlled byvarious controllers in the art such as an engine control unit (ECU), acontrol area network (CAN), and the like. Precise control of the valveopening allows for precise metering of fuel. Fuel injectors provide foreasier starting of an ICE as well as increased fuel efficiency andpotentially cleaner exhaust emissions because the fuel is metered intothe combustion chamber with improved precision and accuracy.

Cleaner emissions can be further improved for an ICE by passing itsexhaust emissions through a device known as a catalytic converter. Sinceexhaust emissions are fairly consistent and predictable, the catalyticconverter can convert some of the more toxic emissions to less toxicsubstances by way of catalyzed chemical reactions. A typical catalyticconverter for a gasoline (petro) fueled ICE in a vehicle is a “threeway” converter. This type of converter converts the main pollutants inautomobile exhaust, namely carbon monoxide (CO), hydrocarbons (unburnedfuel) (CxHx) and oxides of nitrogen (NOx). The catalytic convertercoverts, by a reduction reaction, nitrogen oxides back to nitrogen(i.e., 2NO_(x)→xO₂+N₂). The carbon monoxide components are oxidized tocarbon dioxide (i.e., 2CO+O₂→2CO₂. The un-burnt hydrocarbons areoxidized to carbon dioxide and water (i.e.,C_(x)H_(2x+2)+[(3x+1)/2]O₂→xCO₂+(x+1)H₂O).

Despite these recent advances in the art, improvement in fuel efficiencyand in the reduction if emissions of ICEs are possible and desired.

SUMMARY OF CERTAIN EMBODIMENTS

Broadly speaking, certain embodiments of the invention relate tocontrollers and methods for a fuel injected ICEs, and particularly forcontrolling the fuel injector in a predetermined response to the ICEreaching at least one predetermined parameter of the ICE.

In one embodiment a method of testing the fuel efficiency or theemissions output of an internal combustion engine (ICE) having a fuelinjector is disclosed. At least one operational parameter of the ICE issensed while the ICE is running. The operational parameter has a firstvalue, and the fuel injector is configured to be controlled by changesin the operational parameter. The fuel injector is controlled bysubstituting the first value with a second value when the first valuereaches a predetermined value. The second value does not correspond tothe operational parameter of the ICE while the ICE is running. Then fuelefficiency or the emissions output of the ICE is measured.

In one aspect the at least one operational parameter of the ICE isselected from the group consisting of a manifold pressure, a fuelpressure, an air temperature, an engine combustion chamber temperature,a coolant temperature, a fuel injector temperature, an engine speed, athrottle position, a barometric pressure, an exhaust emissions, acamshaft sensor, an air/fuel mixture, and any combination thereof.

In another aspect the at least one operational parameter of the ICE is acoolant temperature. The controlling of the fuel injector includesadjusting a pulse width of the fuel injector.

In another aspect the adjusting of the pulse width includes reducing thepulse width from a first width to a second width when the coolanttemperature is above 120 degrees Fahrenheit. The first width is a valuebetween about 0.7 and about 1.0 millisecond and the second width is avalue between about 0.05 and about 0.2 millisecond.

In another aspect the fuel injector is controlled by a first electricalsignal prior to the step of controlling the fuel injector. The adjustingof the pulse width includes overriding the first electrical signal witha second electrical signal that is not equal to the first electricalsignal.

In another embodiment, a method of controlling the operation of a fuelinjector of an ICE while it is running includes sensing a temperature ofthe ICE while the ICE is running using a temperature sensor. Temperatureinformation is transmitted from the temperature sensor to a firstcontroller. The operation of the fuel injector is controlled by thefirst controller in response to the temperature information. Thetransmitting of the temperature information from the temperature sensorto the first controller is prevented when the temperature of the ICEreaches a predetermined value. Substitute information is transmittedfrom a second controller to the first controller when the temperature ofthe ICE reaches the predetermined value. The operation of the fuelinjector is controlled by the first controller in response to thesubstitute information.

In one aspect the sensing of the temperature of the ICE includes sensingthe temperature of a coolant of the ICE.

In another aspect the controlling of the fuel injector includesadjusting a pulse width of the fuel injector.

In yet another aspect, the adjusting of the pulse width includesreducing the pulse width from a first width to a second width when thecoolant temperature is above about 120 degrees Fahrenheit. The firstwidth is a value between about 0.7 and about 1.0 millisecond, and thesecond width is a value between about 0.05 and about 0.2 millisecond.

In another embodiment, a device comprises a memory and a processorcoupled to the memory. The processor is operable to perform the steps ofany of the above-described embodiments.

In yet another embodiment, a device to control an internal combustionengine (ICE) having a fuel injector, a temperature sensor, and a firstcontroller is disclosed. The temperature sensor is configured togenerate a plurality of electrical signals that correspond to aplurality of temperatures of the ICE while the ICE is running. The firstcontroller is configured to receive the plurality of electrical signalsand to control the operation of the fuel injector in response to thesesignals. The device includes a memory and a processor coupled to thememory. The processor is operable to receive from the temperature sensorinformation corresponding to the temperature of the ICE. The processoris further operable to transmit substitute temperature information tothe first controller when the temperature of the ICE is within apredetermined range of the plurality of temperatures of the ICE. Thesubstitute temperature information corresponds to a temperature that isdifferent from (i.e., not equal to) the temperature of the ICE when thesubstitute temperature information is being transmitted to the firstcontroller.

In one aspect the processor is further operable to transmit to the firstcontroller information corresponding to the temperature of the ICE whenthe temperature of the ICE is outside of the predetermined range of theplurality of temperatures of the ICE.

In another aspect the device further includes a switch having a firstposition and a second position. When the switch is in the firstposition, the plurality of electrical signals generated by thetemperature sensor is sent to the first controller so that the firstcontroller receives the plurality of electrical signals which have notbeen processed by the processor. On the other hand when the switch is inthe second position, the substitute temperature information istransmitted from the processor to the first controller. The switch isconfigured to actuate between the first and second positions in responseto a command sent by the processor, so that the switch is in the firstposition when the temperature of the ICE is outside the predeterminedrange of the plurality of temperatures of the ICE, and in the secondposition when the temperature of the ICE is within the predeterminedrange of the plurality of temperatures of the ICE.

In yet another aspect the ICE includes a coolant, and the temperaturesensor is a coolant temperature sensor configured to measure thetemperature of the ICE coolant. The predetermined range of the pluralityof temperatures of the ICE is a range between about 120 degrees andabout 250 degrees Fahrenheit.

In yet another embodiment, a non-transitory, computer-readable storagemedium is provided. The storage medium contains instructions that, whenexecuted by a processor, cause the processor to perform the steps of anyof the above-described embodiments.

There are additional aspects to the present inventions. It shouldtherefore be understood that the preceding is merely a brief summary ofsome embodiments and aspects of the present inventions. Additionalembodiments and aspects are referenced below. It should further beunderstood that numerous changes to the disclosed embodiments can bemade without departing from the spirit or scope of the inventions. Thepreceding summary therefore is not meant to limit the scope of theinventions. Rather, the scope of the inventions is to be determined byappended claims and their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects and advantages of the present invention willbecome apparent and more readily appreciated from the followingdescription of certain embodiments, taken in conjunction with theaccompanying drawings of which:

FIG. 1A is a simplified schematic of an engine system according to oneembodiment of the invention;

FIG. 1B is a simplified schematic of the second controller component ofFIG. 1A;

FIG. 1C is a simplified schematic of an alternative embodiment of thesecond controller component of FIG. 1A;

FIG. 2 is a process flow diagram according to another embodiment of theinvention;

FIG. 3 is a graph of the temperature of an internal combustion engine asa function of fuel injector pulse width as is known in the art;

FIG. 4 is a graph of the temperature of an internal combustion engine asa function of fuel injector pulse width according to an embodiment ofthe invention; and

FIG. 5 is a graph of the electrical resistance value in ohms as afunction of temperature for an exemplary temperature sensor.

DETAILED DESCRIPTION

The following description is of the best mode presently contemplated forcarrying out the invention. Reference will be made in detail toembodiments of the present invention, examples of which are illustratedin the accompanying drawings, wherein like reference numerals refer tolike elements throughout. It is understood that other embodiments may beused and structural and operational changes may be made withoutdeparting from the scope of the present invention.

Described herein are controllers and methods for a fuel injected ICE,and particularly controllers and methods for providing an overridesignal for controlling the fuel injector in a predetermined response toat least one predetermined parameter of the ICE.

The following description is not to be taken in a limiting sense, but ismade merely for the purpose of describing the general principles ofexemplary embodiments. The scope of the invention should be determinedwith reference to the claims.

Reference throughout this specification to “one embodiment,” “anembodiment,” “some embodiments,” “some implementations” or similarlanguage means that a particular feature, structure, or characteristicdescribed in connection with the embodiment is included in at least oneembodiment of the present controllers and methods. Thus, appearances ofthe phrases “in one embodiment,” “in an embodiment,” “in someembodiments,” and similar language throughout this specification may,but do not necessarily, all refer to the same embodiment.

Furthermore, the described features, structures, or characteristics ofthe invention may be combined in any suitable manner in one or moreembodiments. In the following description, numerous specific details areprovided, such as examples of programming, software modules,controllers, user selections, hardware modules, hardware circuits,hardware chips, etc., to provide a thorough understanding of embodimentsof the invention. One skilled in the relevant art will recognize,however, that the invention can be practiced without one or more of thespecific details, or with other methods, components, materials, and soforth. In other instances, well-known structures, materials, oroperations are not shown or described in detail to avoid obscuringaspects of the invention.

The controllers and methods can be implemented through hardware and/orsoftware. In one embodiment, the controller comprises a device includingat least one processor, at least one memory or computer readable mediumthat stores and executes computer program code to implement itsfunctionality. Such a controller typically includes a system unit havinga processor and associated volatile and/or non-volatile memory. Such acontroller may also include one or a plurality of I/O devices (i.e.,peripheral devices) which are coupled to the system processor and whichperform specialized functions.

In portions of this disclosure only one compression cycle of onecylinder of an ICE is described for simplicity and in order to aid inthe understanding of certain inventive controllers and methods. It isunderstood though that the descriptions equally apply to multi-cylinderICEs that are working cooperatively through other engine components. Forexample, a camshaft sensor can determine the timing of the fuel injectorpulse to occur in a predetermined position, such as 5 to 15 degreesbefore the top dead center of the compression stroke.

Controllers and methods are provided herein for precision fuel meteringfor delivering measured amounts of fuel to each cylinder of an ICE of atleast once per engine cycle in response to an electronic computer whichmeasures various engine operational and environmental parameters, suchas manifold pressure, fuel pressure, air temperature, combustion chambertemperature, coolant temperature, fuel injector temperature, enginespeed, throttle position, barometric pressure, exhaust emissions,camshaft sensor, air/fuel mixture, as well as a combination of two ormore of these parameters. Such a system provides not only increased fueleconomy and output power, but also reduces vehicle emissions, since lessfuel overall is delivered to the ICE.

In the art, U.S. Pat. No. 3,504,657 to Eichler et al. describesenriching fuel during cold start-ups. It is believed that fuel airmixture must be enriched for cold starting, because part of the fuelcondenses on the cold walls of the intake manifold and only part of thefuel atomizes and becomes available for operation in the engine.Basically, the quantity of fuel required for an engine becomes greateras the engine temperature lowers. Further, the higher the engine speed,the shorter the period of each stroke. Accordingly low-pressureinjection at the time of a start-up may cause a condition where aninjection period within the period of a single stroke results in aninsufficient quantity of fuel being injected, such as for example, whencranking at very low temperatures or when the engine speed is increasingright after a start-up at a low temperature.

In general, certain embodiments of the invention provide novelcontrollers and methods to adjust the fuel injection parameters fordelivering fuel to a combustion chamber to provide a leaner burn than isknown in the art by reducing the time the fuel injector spray valve isopen, thus delivering less fuel than previously has been considered asoptimal in the art. Surprisingly, the reduction of fuel often canprovide reduced hydrocarbon and carbon monoxide emissions without lossof power or fuel efficiency.

The effects of the present embodiments often can be seen most clearly inthe initial vehicle warm up. In these instances, engine coolanttemperature (which is a function of the ICE cylinder temperature) is fedinto a control system for fuel injectors. According to otherembodiments, the temperature of the engine cylinders or the fuelinjector itself can be also considered alone or in any combination withother temperature sensors. In one approach, the fuel delivery parametersfrom the fuel injector can be adjusted to deliver fuel comparable to thelean-burn parameters of a vehicle having coolant operating at 250Fahrenheit (° F.), even during engine warm-up when the ICE coolant infact is much cooler. These parameters can be applied to a vehicle evenwhen the engine coolant temperature is, for example, between 120° F. and250° F. It is noted that the present parameters provide little or noreduction in power or fuel economy since the reduction in hydrocarbonsis the result of more fuel being burned, especially in “cold” engines.

In some aftermarket applications a resistor circuit, or other electroniccomponents (including one or more processors) to modify or override thecoolant temperature sensor output signal, can be used to change the fueldelivery of the fuel injector. In one approach, an aftermarket device orcontroller can be used to override the temperature sensor output at apredetermined ICU temperature reading thereby providing a “ghost” orsubstitute reading or signal to the engine control unit which in turnwill adjust the fuel delivery to a lean-burn mode much more quicklyduring engine warm-up than is preprogrammed into the engine controlunit. According to one embodiment, the device is programmed to overridethe actual temperature sensor signal when the coolant temperaturereaches 120° F., to send this substitute signal to the engine controlunit which in turn results in an increased fuel delivery from the fuelinjector to that of an ICE running as if its coolant temperature was250° F. (although the ICE coolant in fact is not running at thattemperature). The device can also deactivate or remove its substitute or“ghost” signal to the engine control unit when the actual ICE coolanttemperature reaches 250° F. and thereby allow the actual, originaltemperature sensor output signal (or an alternative signal that isessentially the same as that original signal) to be sent to the enginecontrol unit.

Turning now to FIG. 1, there is shown a simplified schematic of anengine system which is generally indicated at reference numeral 20. Thesystem 20 is under the control of a first controller 22, which is acontrol unit such as an Engine Control Unit, a Control Area Network, anindependent controller, a plurality of controllers working alone or invarious combinations, and the like. The first controller 22 essentiallyreceives environmental vehicle inputs (such as such as manifoldpressure, air temperature, engine temperature, coolant temperatures,fuel injector temperature, engine speed, throttle position, barometricpressure, and the like) and applies these inputs to variouspredetermined thresholds and data maps (See e.g., FIGS. 3 and 5) tooutput a desired control to various vehicle components. In this instancefor simplicity, the schematic of the vehicle system 20 just shows atemperature sensor 24 of coolant 28 in the vehicle's coolant loop 26.Here the temperature sensor 24 can read the coolant temperature as apredetermined function of the actual temperature of a cylinder of an ICE30. The sensor 24 can be a standard thermostat or coolant temperaturesensor in the coolant loop 26. The output of the temperature sensor 24could be delivered directly to the first controller 22, and the system20 would be operational. However FIG. 1 illustrates the temperaturesensor 24 output being delivered to a second controller 48 (which inthis embodiment is an aftermarket device) as will be discussed below.

If the second controller 48 was not present in the system 20, thecoolant sensor signal 46 would be sent directly to the first controller22 and compared with stored data thresholds. As a result a command issent to a fuel injector 36 via a first controller output 38. Thiscommand affects the duration that the injector is open for allowing fuelto enter the ICE's combustion chamber. This duration often is referredto as a pulse width. This command, in cooperation with other parameterssuch as throttle position and camshaft position commands, causes thefuel injector 36 to deliver fuel 34 from a fuel line 32 into thecombustion chamber of the ICE 30 where the fuel is ignited, and thenvented as exhaust 42 out of the exhaust line 40.

In some embodiments where the data maps in the first controller 22 fromthe original equipment manufacturer (OEM) are not optimal, anaftermarket solution includes the insertion of a device (i.e., thesecond controller 48) to intercept the output signal of the temperaturesensor 24 and to provide a substitute signal to the first controller 22.The second controller 48 monitors the output of the temperature sensor24 until a predetermined temperature is reached (e.g., 120° F.) theninsert or substitute an altered reading that would correspond to adifferent ICE coolant temperature (e.g., 250° F.) that is not in factthe actual ICE coolant temperature. The second controller 48 continuesto monitor the actual coolant temperature and remove its substitutesignal when the actual coolant temperature falls outside a predeterminedrange (e.g., above 250° F. or below 120° F.). Once actual coolanttemperature readings fall outside the thresholds, the second controller48 allows the actual coolant temperature signal to be sent to the firstcontroller 22. The device could be calibrated using a variety methodsand components, and could be preprogrammed for specific vehicle orengine model applications with known specific pulse width maps. In oneapproach, where the temperature sensor signal is an analog signal wherea change in coolant temperature corresponds to a known change inresistance, the second controller 48 can be a tunable by including avariable resistor, such as one sold under the trademark TRIMPOT. Forexemplary purposes only, in FIG. 5, a sensor output is measured as afunction of engine coolant temperature 94, and mapped at referencenumeral 90. The resistance scale 92 is between about 0.05 ohms and about20,000 ohms.

The controller 22 governs the fuel injector 36 pulse width aspredetermined function of engine coolant 28 temperature. These signalsfrom the fuel injector 36 can alter the flow rate of the fuel and thepulse width of fuel. As an example, the injector can go from a firstpulse width to a second pulse width in response to the sensor readingcrossing above or below 120° F. The pulse width is proportional to theamount of fuel delivered.

FIG. 1B is a simplified block diagram of the second controller 48 ofFIG. 1A according to an embodiment of the invention. The secondcontroller 48 (which in this embodiment is an aftermarket device)includes an analog to digital converter circuit 19, a processor 21, amemory 23 and a digital to analog converter circuit 25. The analog todigital converter circuit 19 receives from the temperature sensor 24 theanalog sensor signal 46 that corresponds to the coolant temperaturebeing detected. The analog to digital converter circuit 19 converts thatsignal 46 to a digital signal for use by the processor 21. The processor21 is connected to the memory 23 for storing programs, data andparameters, including, but not limited to, data corresponding apredetermined range of ICE coolant temperatures that will be used todetermine when to produce an override or substitute signal. AlthoughFIG. 1B shows the memory device 23 as a separate component, alternativeembodiments may use a memory that is integral with the processor 21. Thedigital to analog converter circuit 25 receives digital signals from theprocessor 21, converts them to analog signals, and transmits the analogsignals to the first controller 22 for use by it.

Thus in operation, the processor 21 receives a signal or informationcorresponding to the temperature of an ICE. This is compared withpredetermined temperature-related data that is stored in the memory 23,and the processor 21 takes the appropriate action using program logic.For example, if the received temperature information falls within apredetermined temperature range, then the processor sends to the firstcontroller 22 (via the digital to analog circuit 25) substituteinformation corresponding to a temperature that is different from thatwhich actually is being detected by the temperature sensor 24. In otherwords the processor 21 causes a substitute or override signal (that doesnot reflect the true ICE temperature) to be sent to the first controller22. On the other hand if the received temperature information is outsidethe predetermined temperature range, then a substitute signalcorresponding to a temperature that is the same (or essentially thesame) as that which actually is being detected by the temperature sensor24 is sent by the processor 21 to the first controller 22. In otherwords, the processor 21 effectively operates as if the second controller48 was not present in the system by sending the first controller 22 thissubstitute signal that is indicative of the true ICE temperature.

FIG. 1C is a simplified block diagram of a second controller 48 a ofFIG. 1A according to an alternative embodiment of the invention. Thesecond controller 48 a includes the analog to digital converter circuit19, the processor 21, the memory 23 and the digital to analog convertercircuit 25, all of which are similar to that illustrated and describedin connection with FIG. 1B. The analog to digital converter circuit 19receives from the temperature sensor 24 the analog sensor signal 46 thatcorresponds to the coolant temperature being detected. The analog todigital converter circuit 19 converts that signal 46 to a digital signalfor use by the processor 21. The processor 21 is connected to the memory23 for storing programs, data and parameters, etc. The digital to analogconverter circuit 25 receives digital signals from the processor 21 andconverts them to analog signals.

However the second controller 48 a of FIG. 1C further includes a seconddigital to analog converter circuit 27 which received commands from theprocessor 21 and which has an output connected to a solenoid-operatedswitch 29. A first input terminal 31 of the switch 29 is electricallyconnected to the output of the first digital to analog converter circuit25. A second input terminal 33 of the switch 29 is connected to a bypassline or circuit 37 which receives the analog signal 46 directly from thetemperature sensor 24. An output terminal 35 of the switch 29 isconnected to the first controller 22. A signal for operating oractuating the switch 29 is received from the second digital to analogconverter circuit 27, which in turn receives a digital signal or commandfrom the processor 21. The switch 29 can be in a first position wherebythe output terminal 35 is connected to the second terminal 33.Alternatively the switch 29 can be in a second position whereby theoutput terminal 35 is connected to the first terminal 31.

The switch 29 is normally in its first position so that when it is notreceiving an actuating signal from the second digital to analogconverter circuit 27, the output terminal 35 of the switch 29 isconnected to its second terminal 33. Accordingly the signal 46 from thetemperature sensor 24 is sent to the first controller 22 so that itreceives a signal which has not been processed by the processor 21. Thusthe signal that is received by the first controller 22 traveled via thebypass circuit 37 and thereby bypassed the analog to digital circuit 19,the processor 21 and the first digital to analog circuit 25, essentiallyas if the second controller 48 a was not present in the system 20. (Thisis advantageous in the event that there is loss of power or a failure ofthe other components of the second controller 48 a, in which event thefirst controller 22 will continue to receive a signal from thetemperature sensor 24.) On the other hand when the program logicdictates that an override signal should be sent to the first controller22, the processor 21 transmits the appropriate signal to the seconddigital to analog converter circuit 27 which in turn transmits an analogsignal or voltage to the switch 29 thereby actuating it and causing itto change from its first position to its second position. This action inturn isolates the direct feed from the temperature sensor 24 and permitsthe processor 21 to transmit signals, including substitute temperatureinformation, to the first controller 22.

One of ordinary skill in the art will appreciate that the program logicdescribed herein may be implemented in alternative embodiments inhardware, software, firmware, or a combination thereof. The programlogic can be implemented in software or firmware that is stored inmemory and that is executed by a processor. If implemented in hardware,the logic may be implemented in any one or combination of volatilememory devices (e.g., random access memory (RAM, such as DRAM, SRAM,SDRAM, etc.)) and nonvolatile memory devices (e.g., ROM, EPROM, harddrive, etc.).

Memory may incorporate electronic, magnetic, optical, and/or other typesof storage media. Memory may also have a distributed architecture, wherevarious components are situated remotely from one another. Ifimplemented in hardware, the logic may be implemented with any or acombination of the following technologies, which are all known in theart: one or more discrete logic circuits for implementing logicfunctions upon data signals, an application specific integrated circuit(ASIC), a programmable gate array(s) (PGA), a field programmable gatearray (FPGA), etc.

As shown in FIG. 3, a graph 70 is shown that maps values for acontroller to apply for a typical correlation of fuel injector pulsewidth, such that there is a generally linear decrease in pulse width 74as ICE coolant temperature 72 increases. Thus this reflects theoperation of a fuel injector without the use of an override controller,such as the second controller 48 of FIG. 1A. The extremes are shown as apulse width of 0.1 ms duration for an engine coolant at approximately260° F. (essentially a mist) to a pulse width of about 0.8 ms for anengine coolant at about 75° F. (For many fuel injectors a 0.8 ms pulsewidth results in an essentially solid stream of fuel, i.e., a “rich”burn.) It is a goal of embodiments of the present invention to introducea lean burn earlier during the engine warm-up phase than shown by thegraph of FIG. 3. FIG. 4 shows one embodiment where the generally linearpattern of decreasing pulse width is interrupted for a temperature rangebetween about 120° F. and about 250° F. to a value such that the fuelinjector pulse width (corresponding to an engine coolant at 250° F.)remains essentially the same for this 120° F. to 250° F. temperaturerange, as shown at reference numeral 70 i. Thus, the pulse width for acoolant temperature between 120° F. and 250° F. remains approximatelyconstant at 0.1 ms throughout this temperature range. It is notedhowever that many other variations of the lean burn rate are possible.

A process flow diagram for a method of controlling a fuel injectoraccording to one embodiment of the invention is shown in FIG. 2generally at reference numeral 50. As shown, a controller is initiatedat an engine_on event (step 52), which initiates sensing of one or moreenvironmental parameters of the ICE, such as coolant temperature. (step54) Once the temperature is sensed the controller compares the inputtedtemperature value as taken from a temperature sensor with apredetermined threshold as taken from data stored in memory, such asdata from a data table. (step 56) Next a determination is made whether athreshold has been reached. (step 60) If not, the process returns backto the compare step 56. If yes at step 60, a command is initiated toadjust the pulse width according to a predetermined pulse widthretrieved from data stored in the memory. (step 62).

Table 1 below shows what are believed to be typical standardizedemissions results for gasoline and diesel motors for engines runningunder load.

TABLE 1 (Standardized Emissions results based on an engine running underload) Gasoline Engine Diesel Engine Compound % of total Compound % oftotal N₂ 71 N₂ 67 CO₂ 14 CO₂ 13 H₂O 12 H₂O 11 CO 1-2 O₂ 10 Traceelements <0.5 Trace elements ~0.3 NO_(x) <0.25 NO_(x) <0.15 C_(x)H_(y)<0.25 CO <0.045 SO₂ possible traces PM <0.045 C_(x)H_(y) <0.03 SO₂ <0.03where: N₂ = Nitrogen CO₂ = Carbon dioxide H₂O = Water O₂ = OxygenC_(x)H_(y) (or Hx or HC) = Hydrocarbons CO = Carbon Monoxide NO_(x) =Nitrogen oxides SO₂ = Sulphur dioxide PM = Particulate matter

The emissions of an ICE can be tested and in some cases reduced,however, using embodiments of the present invention. To conduct a testemission results are read from the same test engine under comparableconditions both with and without a controller (such as for example thesecond controller 48/48 a of FIGS. 1A-1C) according to an embodiment ofthe invention. A stock engine is used as a benchmark control for theengine's exhaust emissions for comparison when the inventive controllerwas included. It is noted that there are many ways to test using thepresent embodiments. These were chosen as just one way to demonstratethe effectiveness of the controllers. According to one method, exhaustemissions are measured using an unmodified 5 Gas analyzer sold under thetrade mark SNAP-ON HH GAB5. Testing results are for gas concentrationsof: oxygen (O2) by percent volume; carbon monoxide (CO) by percentvolume; carbon dioxide (CO2) by percent volume; hydrocarbons (CxHy) byparts per million (ppm); and oxides of nitrogen (NOx) by ppm.

The air-fuel ratio (AFR) is also measured and is the mass ratio of airto fuel present in an ICE. If exactly enough air is provided tocompletely burn all of the fuel, the ratio is known as the“stoichiometric” mixture. AFR is an important measure for anti-pollutionand performance-tuning reasons. The lower the excess air, the “richer”the flame. A stoichiometric mixture is considered to have an AFR thathas just enough air to completely burn the available fuel. This israrely achieved in an ICE given the very short time available for thefuel to burn in the combustion chamber for each combustion cycle. Forexample, in some ICE models this is only about 4-5 milliseconds at anengine speed of 6000 rpm. This is the time that elapses from when aspark is fired until the burning of the fuel air mix is essentiallycomplete after some 80 degrees of crankshaft rotation.

Catalytic converters are designed to work best when the exhaust gasespassing through them are the result of the nearly ideal combustion of astoichiometric mixture. Unfortunately, a mixture of this type burns veryhot and can damage engine components if the engine is placed under highload at this fuel-air mixture. Accordingly, stoichiometric mixtures areonly preferred under light load conditions. For acceleration and highload conditions, a richer mixture (lower air-fuel ratio) is used toproduce cooler combustion products and thereby prevent overheating ofthe cylinder head. For a gasoline fuel, the stoichiometric air-fuelmixture is approximately 13:1, but U.S. Federal environmentalregulations raised the ratio to 14.7:1 to allow the use of catalyticconverters. That is, for every one gram of fuel, 14.7 grams of air arerequired. Any mixture less than 14.7 to 1 is considered to be a richmixture; any more than 14.7 to 1 is a lean mixture under idealconditions.

As previously mentioned, a catalytic converter is effective to reducenitrogen oxides to nitrogen, carbon monoxide to carbon dioxide, andhydrocarbons to carbon dioxide and water. However, many ICEs generatesignificant pollution during the first five minutes of operation, whichis before the catalytic converter has warmed up sufficiently to even beeffective.

Embodiments of the present invention are effective for reducing carbonmonoxide beyond the effect of the catalytic converter. For example, forsome ICE models or designs hydrocarbon emissions of a cold engine atidle are relatively unchanged by the catalytic converter, as would bepredicted for a cold catalytic converter. When the controller of oneembodiment is used however, the emission of hydrocarbons, even on a coldstart engine, are expected to drop to zero or near zero. Also carbonmonoxide emissions should also drop from 1.77 percent volume to 0.09percent volume when cooperating with the catalytic converter. Aspredicted, the CO2 emissions increased.

In other ICE models or designs, the catalytic converter is fullyfunctioning and handling the removal of hydrocarbons, while thecontroller of one embodiment of the invention is effective in loweringCO emission. Similar results are expected for a cold engine under load(of certain ICE models) where the catalytic converter working incooperation with the controller was able to effectively eliminatehydrocarbons and significantly reduce CO emission.

In view of the above, it will be appreciated that certain embodiments ofthe invention overcome many of the long-standing problems in the art byproviding controllers and methods for controlling a fuel injector of anICE by providing an override signal so that the fuel injector is causedto operate according to at least one predetermined parameter of the ICE.

While the description above refers to particular embodiments of thepresent invention, it will be understood that many modifications may bemade without departing from the spirit thereof. The claims are intendedto cover such modifications as would fall within the true scope andspirit of the present invention. The presently disclosed embodiments aretherefore to be considered in all respects as illustrative and notrestrictive, the scope of the invention being indicated by the claimsrather than the foregoing description, and all changes which come withinthe meaning and range of equivalency of the claims are thereforeintended to be embraced therein.

What is claimed is:
 1. A method of testing the fuel efficiency of aninternal combustion engine (ICE) having a fuel injector, comprising:sensing, via at least one sensor, at least one operational parameter ofthe ICE while the ICE is running, wherein the operational parameter hasa first value, and wherein the fuel injector is configured to becontrolled by changes in the operational parameter; controlling the fuelinjector by substituting the first value with a second value when thefirst value reaches a predetermined value, wherein an injector sprayvalve of the fuel injector is maintained in an open position for a timesufficient to deliver an amount of fuel to the ICE based on the secondvalue, and wherein the second value does not correspond to theoperational parameter of the ICE while the ICE is running; measuring thefuel efficiency of the ICE after the controlling of the fuel injector;and further comprising monitoring the first value after the substitutingof the first value with the second value, and controlling the fuelinjector by removing the substituted second value when the first valuefalls outside of a predetermined range during the controlling of thefuel injector with the substituted second value.
 2. The method of claim1 wherein the at least one operational parameter of the ICE is selectedfrom the group consisting of a manifold pressure, a fuel pressure, anair temperature, an engine combustion chamber temperature, a coolanttemperature, a fuel injector temperature, an engine speed, a throttleposition, a barometric pressure, an exhaust emissions, a camshaftsensor, and an air/fuel mixture.
 3. The method of claim 1, wherein theat least one operational parameter of the ICE is a coolant temperatureand wherein the controlling of the fuel injector includes adjusting apulse width of the fuel injector.
 4. The method of claim 3, wherein theadjusting of the pulse width includes reducing the pulse width from afirst width to a second width when the coolant temperature is above 120degrees Fahrenheit, wherein the first width is a value between about 0.7and about 1.0 millisecond and the second width is a value between about0.05 and about 0.2 millisecond.
 5. The method of claim 3, wherein thefuel injector is controlled by a first electrical signal prior to thestep of controlling the fuel injector, and wherein the adjusting of thepulse width includes overriding the first electrical signal with asecond electrical signal that is not equal to the first electricalsignal.
 6. A method of testing the emissions output of an internalcombustion engine (ICE) having a fuel injector, comprising: sensing, viaat least one sensor, a temperature of the ICE while the ICE is running,wherein the temperature is a first value and wherein the fuel injectoris configured to be controlled by the temperature of the ICE;controlling the fuel injector by substituting the first value with asecond value when the first value reaches a predetermined value, whereinan injector spray valve of the fuel injector is maintained in an openposition for a time sufficient to deliver an amount of fuel to the ICEbased on the second value, and wherein the second value does notcorrespond to the temperature of the ICE while the ICE is running;measuring the emissions of the ICE after the controlling of the fuelinjector; and further comprising monitoring the first value after thesubstituting of the first value with the second value, and controllingthe fuel injector by removing the substituted second value when thefirst value falls outside of a predetermined range during thecontrolling of the fuel injector with the substituted second value. 7.The method of claim 6, wherein the measuring of the emissions of the ICEincludes measuring a CO level in an exhaust of the ICE using a CO sensordisposed within the exhaust.
 8. The method of claim 6, wherein thesensing of the temperature of the ICE includes sensing the temperatureof a coolant of the ICE.
 9. The method of claim 6, wherein thecontrolling of the fuel injector includes adjusting a pulse width of thefuel injector.
 10. The method of claim 9, wherein the adjusting of thepulse width includes reducing the pulse width from a first width to asecond width when the coolant temperature is above 120 degreesFahrenheit, wherein the first width is a value between about 0.7 andabout 1.0 millisecond and the second width is a value between about 0.05and about 0.2 millisecond.
 11. The method of claim 9, wherein the fuelinjector is controlled by a first electrical signal prior to the step ofcontrolling the fuel injector, and wherein the adjusting of the pulsewidth includes overriding the first electrical signal with a secondelectrical signal that is not equal to the first electrical signal. 12.A method of controlling the operation of a fuel injector of an internalcombustion engine (ICE) while the ICE is running, comprising: sensing atemperature of the ICE while the ICE is running using a temperaturesensor; transmitting temperature information from the temperature sensorto a first controller; controlling the operation of the fuel injector bythe first controller in response to the temperature information, whereinan injector spray valve of the fuel injector is maintained in an openposition for a time sufficient to deliver an amount of fuel to the ICEbased on the temperature information; preventing the transmitting of thetemperature information from the temperature sensor to the firstcontroller when the temperature of the ICE reaches a predeterminedvalue; transmitting substitute information from a second controller tothe first controller when the temperature of the ICE reaches thepredetermined value; controlling the operation of the fuel injector bythe first controller in response to the substitute information, whereinan injector spray valve of the fuel injector is maintained in an openposition for a time sufficient to deliver an amount of fuel to the ICEbased on the substitute information; and further comprising monitoringthe temperature information after the transmitting of the substitutetemperature information from the second controller to the firstcontroller, and controlling the operation of the fuel injector by thefirst controller via removing the substituted temperature informationwhen the temperature information transmitted from the temperature sensorto the first controller falls outside of a predetermined range duringthe controlling of the fuel injector with the substituted temperatureinformation.
 13. The method of claim 12, wherein the sensing of thetemperature of the ICE includes sensing the temperature of a coolant ofthe ICE.
 14. The method of claim 13, wherein the controlling of the fuelinjector includes adjusting a pulse width of the fuel injector.
 15. Themethod of claim 14, wherein the adjusting of the pulse width includesreducing the pulse width from a first width to a second width when thecoolant temperature is above about 120 degrees Fahrenheit, wherein thefirst width is a value between about 0.7 and about 1.0 millisecond andthe second width is a value between about 0.05 and about 0.2millisecond.
 16. A device to control an internal combustion engine (ICE)having a fuel injector, a temperature sensor, and a first controller,wherein the temperature sensor is configured to generate a plurality ofelectrical signals that correspond to a plurality of temperatures of theICE while the ICE is running, wherein the first controller is configuredto receive the plurality of electrical signals and to control theoperation of the fuel injector in response to the plurality ofelectrical signals, the device comprising: a memory and a processorcoupled to the memory and operable to: receive from the temperaturesensor information corresponding to the temperature of the ICE; transmitsubstitute temperature information to the first controller when thetemperature of the ICE is within a predetermined range of the pluralityof temperatures of the ICE, wherein an injector spray valve of the fuelinjector is maintained in an open position for a time sufficient todeliver an amount of fuel to the ICE based on the substitute temperatureinformation, wherein the substitute temperature information correspondsto a temperature that is not equal to the temperature of the ICE whenthe substitute temperature information is being transmitted to the firstcontroller; and wherein the processor is further operable to monitor thetemperature sensor information after the substitute temperatureinformation is transmitted to the first controller, and to control theoperation of the fuel injector via removing the substituted temperatureinformation when the temperature sensor information falls outside of apredetermined range during control of the fuel injector with thesubstituted temperature information.
 17. The device of claim 16 whereinthe processor is further operable to transmit to the first controllerinformation corresponding to the temperature of the ICE when thetemperature of the ICE is outside of the predetermined range of theplurality of temperatures of the ICE.
 18. The device of claim 16 furthercomprising a switch having a first position and a second position,wherein the device is configured so that when the switch is in the firstposition, the plurality of electrical signals generated by thetemperature sensor is sent to the first controller so that the firstcontroller receives the plurality of electrical signals which have notbeen processed by the processor, wherein the device is furtherconfigured so that when the switch is in the second position, thesubstitute temperature information is transmitted from the processor tothe first controller, and wherein the switch is configured to actuatebetween the first and second positions in response to a command sent bythe processor, so that the switch is in the first position when thetemperature of the ICE is outside the predetermined range of theplurality of temperatures of the ICE, and the switch is in the secondposition when the temperature of the ICE is within the predeterminedrange of the plurality of temperatures of the ICE.
 19. The device ofclaim 16 wherein the ICE further includes a coolant, wherein thetemperature sensor is a coolant temperature sensor configured to measurethe temperature of the ICE coolant, and wherein the predetermined rangeof the plurality of temperatures of the ICE is a range between about 120degrees and about 250 degrees Fahrenheit.